Spalling. which can be classified into sub-surface and surface-originated types. is a major failure mode of rolling bearings due to rolling contact fatigue (RCF). Sub-surface originated spalling typically has a much longer life than surface-originated spalling. https://www.nacrack.com/hot-choice-Open-Box-Verona-Wig-by-BelleTress-Heat-Friendly-Synthetic-Hair-Average-Cap-Buttered-Toast-R-great-buy/